Hi,
In the current draft of CSS Animations we have both:
(4.3 The animation-duration property)
"If the <time> is 0s, like the initial value, the keyframes of the
animation have no effect, but the animation itself still occurs
instantaneously. That is, animation-fill-mode applies as normal,
filling backwards or forwards as appropriate, and animation events
still fire."
http://dev.w3.org/csswg/css-animations/#propdef-animation-duration
And later:
(5 Animation Events)
"Any animation for which both a valid keyframe rule and a non-zero
duration are defined will run and generate events; this includes
animations with empty keyframe rules.
"Issue: This contradicts the animation-delay section, which says that
a 0s duration animation still fires events."
http://dev.w3.org/csswg/css-animations/#events
I believe 4.3 is correct and is now consistently implemented in all
major browsers.[1] Is there any reason not to fix the second reference
to simply drop the "non-zero duration" condition?
Best regards,
Brian
[1] We fixed this in Firefox only recently:
https://bugzilla.mozilla.org/show_bug.cgi?id=1004365
See https://bug1004365.bugzilla.mozilla.org/attachment.cgi?id=8415743
for a test case